Empty containers, such as PET (polyethylene terephthalate) bottles, are known in the art as intended for filling with a liquid beverage. Such containers typically become contaminated with foreign material, such as paper, wood dust, or plastic debris during shipping, even when they are stored in boxes or other carrying receptacles. The bottles can also become contaminated as they are being processed prior to filling. During processing, contact between the containers and the surfaces of articles, such as conveyors or carriers, used to convey the containers, cause the containers to pick up a small amount of net electrostatic charge, thereby rendering the containers capable of attracting fine particles to the containers' internal and external walls. Thus, the need to rinse or otherwise clean the containers prior to filling is necessary to ensure that the beverages are acceptable to the ultimate consumer.
The dust particles contaminating these containers are characteristically extremely small, often measuring less than 10 microns in diameter. Any electrostatic charges on the containers induce opposite charges on the particles to attract and hold the particles on the containers' walls. To remove particles adhering to the walls, these opposite charges must be neutralized. Neutralizing the charges is difficult, however, because the charges holding each dust particle to a container wall are shielded by the dust particle itself. Moreover, once the electrostatic forces have been momentarily abated, the freed dust particles must be removed immediately before they re-attach themselves to a container.
Several prior art methods have been used to rinse the inside of a container or bottle. The methods include spraying the containers with water including hot water in certain methods. Methods using ozone or ozonated water as a sanitizing agent have also been used. Chemical disinfectants have typically been considered unsuitable such as in hot-fill operations. Finally, ionized gas streams have been used to rinse containers. Combinations of air and water rinsing have also been used. Certain disadvantages are associated with these methods including a greater use of energy and natural resources. In addition, these methods often require that the bottles be inverted prior to as well as during the rinsing process wherein gravity can assist in channeling contaminants away from the bottles. This requires additional bottle handling mechanisms to invert the bottles as well as to re-position the bottles right side up in preparation for filling with a liquid beverage.
Thus, while container rinsing systems according to the prior art provide a number of advantageous features, they nevertheless have certain limitations. The present invention seeks to overcome certain of these limitations and other drawbacks of the prior art, and to provide new features not heretofore available.